This is a major change on how we represent nested name qualifications in
the AST.
* The nested name specifier itself and how it's stored is changed. The
prefixes for types are handled within the type hierarchy, which makes
canonicalization for them super cheap, no memory allocation required.
Also translating a type into nested name specifier form becomes a no-op.
An identifier is stored as a DependentNameType. The nested name
specifier gains a lightweight handle class, to be used instead of
passing around pointers, which is similar to what is implemented for
TemplateName. There is still one free bit available, and this handle can
be used within a PointerUnion and PointerIntPair, which should keep
bit-packing aficionados happy.
* The ElaboratedType node is removed, all type nodes in which it could
previously apply to can now store the elaborated keyword and name
qualifier, tail allocating when present.
* TagTypes can now point to the exact declaration found when producing
these, as opposed to the previous situation of there only existing one
TagType per entity. This increases the amount of type sugar retained,
and can have several applications, for example in tracking module
ownership, and other tools which care about source file origins, such as
IWYU. These TagTypes are lazily allocated, in order to limit the
increase in AST size.
This patch offers a great performance benefit.
It greatly improves compilation time for
[stdexec](https://github.com/NVIDIA/stdexec). For one datapoint, for
`test_on2.cpp` in that project, which is the slowest compiling test,
this patch improves `-c` compilation time by about 7.2%, with the
`-fsyntax-only` improvement being at ~12%.
This has great results on compile-time-tracker as well:
This patch also further enables other optimziations in the future, and
will reduce the performance impact of template specialization resugaring
when that lands.
It has some other miscelaneous drive-by fixes.
About the review: Yes the patch is huge, sorry about that. Part of the
reason is that I started by the nested name specifier part, before the
ElaboratedType part, but that had a huge performance downside, as
ElaboratedType is a big performance hog. I didn't have the steam to go
back and change the patch after the fact.
There is also a lot of internal API changes, and it made sense to remove
ElaboratedType in one go, versus removing it from one type at a time, as
that would present much more churn to the users. Also, the nested name
specifier having a different API avoids missing changes related to how
prefixes work now, which could make existing code compile but not work.
How to review: The important changes are all in
`clang/include/clang/AST` and `clang/lib/AST`, with also important
changes in `clang/lib/Sema/TreeTransform.h`.
The rest and bulk of the changes are mostly consequences of the changes
in API.
PS: TagType::getDecl is renamed to `getOriginalDecl` in this patch, just
for easier to rebasing. I plan to rename it back after this lands.
Fixes#136624
Fixes https://github.com/llvm/llvm-project/issues/43179
Fixes https://github.com/llvm/llvm-project/issues/68670
Fixes https://github.com/llvm/llvm-project/issues/92757
Instead of manually adding a note pointing to the relevant template
parameter to every relevant error, which is very easy to miss, this
patch adds a new instantiation context note, so that this can work using
RAII magic.
This fixes a bunch of places where these notes were missing, and is more
future-proof.
Some diagnostics are reworked to make better use of this note:
- Errors about missing template arguments now refer to the parameter
which is missing an argument.
- Template Template parameter mismatches now refer to template
parameters as parameters instead of arguments.
It's likely this will add the note to some diagnostics where the
parameter is not super relevant, but this can be reworked with time and
the decrease in maintenance burden makes up for it.
This bypasses the templight dumper for the new context entry, as the
tests are very hard to update.
This depends on #125453, which is needed to avoid losing the context
note for errors occuring during template argument deduction.
Currently, if the argument to `__builtin_assume` and friends contains
side-effects, we issue the following diagnostic:
```
<source>:1:34: warning: the argument to '__builtin_assume' has side
effects that will be discarded [-Wassume]
1 | void f(int x) { __builtin_assume(x++); }
|
```
The issue here is that this diagnostic misrepresents what is actually
happening: not only do we discard the side-effects of the expression,
but we also don’t even emit any assumption information at all because
the backend is not equipped to deal with eliminating side-effects in
cases such as this.
This has caused some confusion (see #91612) beacuse the current wording
of the warning suggests that, sensibly, only the side-effects of the
expression, and not the assumption itself, will be discarded.
This pr updates the diagnostic to state what is actually happening: that
the assumption has no effect at all because its argument contains
side-effects:
```
<source>:1:34: warning: assumption is ignored because it contains
(potential) side-effects [-Wassume]
1 | void f(int x) { __builtin_assume(x++); }
|
```
I’ve deliberately included ‘(potential)’ here because even expressions
that only contain potential side-effects (e.g. `true ? x : x++` or a
call to a function that is pure, but we don’t know that it is) cause the
assumption to be discarded. This, too, has caused some confusion because
it was erroneously assumed that Clang would e.g. infer that a function
call is pure and not discard the assumption as a result when that isn’t
the case.
This is intended to be temporary; we should revert back to the original
diagnostic once we have proper support for assumptions with side-effects
in the backend (in which case the side-effects will still be discarded,
but the assumption won’t)
This fixes#91612.
The attributes changes were left out of Clang 17.
Attributes that used to take a string literal now accept an unevaluated
string literal instead, which means they reject numeric escape sequences
and strings literal with an encoding prefix - but the later was already
ill-formed in most cases.
We need to know that we are going to parse an unevaluated string literal
before we do - so we can reject numeric escape sequence,
so we derive from Attrs.td which attributes parameters are expected
to be string literals.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D156237
For backwards compatiblity, we emit only a warning instead of an error if the
attribute is one of the existing type attributes that we have historically
allowed to "slide" to the `DeclSpec` just as if it had been specified in GNU
syntax. (We will call these "legacy type attributes" below.)
The high-level changes that achieve this are:
- We introduce a new field `Declarator::DeclarationAttrs` (with appropriate
accessors) to store C++11 attributes occurring in the attribute-specifier-seq
at the beginning of a simple-declaration (and other similar declarations).
Previously, these attributes were placed on the `DeclSpec`, which made it
impossible to reconstruct later on whether the attributes had in fact been
placed on the decl-specifier-seq or ahead of the declaration.
- In the parser, we propgate declaration attributes and decl-specifier-seq
attributes separately until we can place them in
`Declarator::DeclarationAttrs` or `DeclSpec::Attrs`, respectively.
- In `ProcessDeclAttributes()`, in addition to processing declarator attributes,
we now also process the attributes from `Declarator::DeclarationAttrs` (except
if they are legacy type attributes).
- In `ConvertDeclSpecToType()`, in addition to processing `DeclSpec` attributes,
we also process any legacy type attributes that occur in
`Declarator::DeclarationAttrs` (and emit a warning).
- We make `ProcessDeclAttribute` emit an error if it sees any non-declaration
attributes in C++11 syntax, except in the following cases:
- If it is being called for attributes on a `DeclSpec` or `DeclaratorChunk`
- If the attribute is a legacy type attribute (in which case we only emit
a warning)
The standard justifies treating attributes at the beginning of a
simple-declaration and attributes after a declarator-id the same. Here are some
relevant parts of the standard:
- The attribute-specifier-seq at the beginning of a simple-declaration
"appertains to each of the entities declared by the declarators of the
init-declarator-list" (https://eel.is/c++draft/dcl.dcl#dcl.pre-3)
- "In the declaration for an entity, attributes appertaining to that entity can
appear at the start of the declaration and after the declarator-id for that
declaration." (https://eel.is/c++draft/dcl.dcl#dcl.pre-note-2)
- "The optional attribute-specifier-seq following a declarator-id appertains to
the entity that is declared."
(https://eel.is/c++draft/dcl.dcl#dcl.meaning.general-1)
The standard contains similar wording to that for a simple-declaration in other
similar types of declarations, for example:
- "The optional attribute-specifier-seq in a parameter-declaration appertains to
the parameter." (https://eel.is/c++draft/dcl.fct#3)
- "The optional attribute-specifier-seq in an exception-declaration appertains
to the parameter of the catch clause" (https://eel.is/c++draft/except.pre#1)
The new behavior is tested both on the newly added type attribute
`annotate_type`, for which we emit errors, and for the legacy type attribute
`address_space` (chosen somewhat randomly from the various legacy type
attributes), for which we emit warnings.
Depends On D111548
Reviewed By: aaron.ballman, rsmith
Differential Revision: https://reviews.llvm.org/D126061
this patch fixes Bug 27113 by adding support for string literals to the
implementation of the MS extension __identifier.
Differential revision: https://reviews.llvm.org/D100252
The current C++ grammar allows an anonymous bit-field with an attribute,
but this is ambiguous (the attribute in that case could appertain to the
type instead of the bit-field). The current thinking in the Core Working
Group is that it's better to disallow attributes in that position at the
grammar level so that the ambiguity resolves in favor of applying to the
type.
During discussions about the behavior of the attribute, the Core Working
Group also felt it was better to disallow anonymous bit-fields from
specifying a default member initializer.
This implements both sets of related grammar changes.
This changes some diagnostics to use terminology from the standard
rather than invented terminology, which improves consistency with other
diagnostics as well. There are no functional changes intended other
than wording and naming.
Objective-C++11 and under MS extensions.
This matches the MSVC behavior, and means that Objective-C behaves as a
set of extensions to the base language, rather than replacing the base
language rule with a different one.
The 'class' or 'struct' keyword is only permitted as part of either an
enum definition or a standalone opaque-enum-declaration, not as part of
an elaborated type specifier. We previously failed to diagnose this, and
generally didn't properly implement the restrictions on elaborated type
specifiers for enumeration types.
In passing, also fixed incorrect parsing for enum-bases, which we
previously parsed as a type-name, but are actually a type-specifier-seq.
This matters for cases like 'enum E : int *p;', which is valid as a
Microsoft extension.
Plus some minor parse diagnostic improvements.
Bumped the recently-added ExtWarn for 'enum E : int x;' to be
DefaultError; this is not an intentional extension, so producing an
error by default seems appropriate, but the warning flag to disable it
may still be useful for code written against old Clang. The same
treatment is given here to the diagnostic for 'enum class E x;', which
we similarly have incorrectly accepted for many years. These diagnostics
continue to be suppressed under -fms-extensions and when compiling
Objective-C code. We will need to decide separately whether Objective-C
should follow the C++ rules or the (older) MSVC rules.
Summary:
Previously, we treated CXXUuidofExpr as quite a special case: it was the
only kind of expression that could be a canonical template argument, it
could be a constant lvalue base object, and so on. In addition, we
represented the UUID value as a string, whose source form we did not
preserve faithfully, and that we partially parsed in multiple different
places.
With this patch, we create an MSGuidDecl object to represent the
implicit object of type 'struct _GUID' created by a UuidAttr. Each
UuidAttr holds a pointer to its 'struct _GUID' and its original
(as-written) UUID string. A non-value-dependent CXXUuidofExpr behaves
like a DeclRefExpr denoting that MSGuidDecl object. We cache an APValue
representation of the GUID on the MSGuidDecl and use it from constant
evaluation where needed.
This allows removing a lot of the special-case logic to handle these
expressions. Unfortunately, many parts of Clang assume there are only
a couple of interesting kinds of ValueDecl, so the total amount of
special-case logic is not really reduced very much.
This fixes a few bugs and issues:
* PR38490: we now support reading from GUID objects returned from
__uuidof during constant evaluation.
* Our Itanium mangling for a non-instantiation-dependent template
argument involving __uuidof no longer depends on which CXXUuidofExpr
template argument we happened to see first.
* We now predeclare ::_GUID, and permit use of __uuidof without
any header inclusion, better matching MSVC's behavior. We do not
predefine ::__s_GUID, though; that seems like a step too far.
* Our IR representation for GUID constants now uses the correct IR type
wherever possible. We will still fall back to using the
{i32, i16, i16, [8 x i8]}
layout if a definition of struct _GUID is not available. This is not
ideal: in principle the two layouts could have different padding.
Reviewers: rnk, jdoerfert
Subscribers: arphaman, cfe-commits, aeubanks
Tags: #clang
Differential Revision: https://reviews.llvm.org/D78171
object rather than tracking the originating expression.
This is groundwork for supporting polymorphic typeid expressions. (Note
that this somewhat regresses our support for DR1968, but it turns out
that that never actually worked anyway, at least in non-trivial cases.)
This reinstates r360974, reverted in r360988, with a fix for a
static_assert failure on 32-bit builds: force Type base class to have
8-byte alignment like the rest of Clang's AST nodes.
llvm-svn: 360995
object rather than tracking the originating expression.
This is groundwork for supporting polymorphic typeid expressions. (Note
that this somewhat regresses our support for DR1968, but it turns out
that that never actually worked anyway, at least in non-trivial cases.)
llvm-svn: 360974
Clang emits a warning when using a pure specifier =0 in a function definition
at class scope (a MS-specific construct), when using -fms-extensions.
However, to detect this, it was using FD->isCanonicalDecl() on function
declaration, which was also detecting out-of-class definition of member
functions of class templates. Fix this by using !FD->isOutOfLine() instead.
Fixes PR21334.
Differential Revision: https://reviews.llvm.org/D29707
Reviewed By: riccibruno
Reviewers: rnk, riccibruno
Patch By: Rudy Pons
llvm-svn: 358849
We need to treat __unaligned like the other 'cvr' qualifiers when it
appears at the end of a function prototype. We weren't doing that in
some tentative parsing.
Fixes PR36638.
llvm-svn: 326962
This also clarifies some terminology used by the diagnostic (methods -> Objective-C methods, fields -> non-static data members, etc).
Many of the tests needed to be updated in multiple places for the diagnostic wording tweaks. The first instance of the diagnostic for that attribute is fully specified and subsequent instances cut off the complete list (to make it easier if additional subjects are added in the future for the attribute).
llvm-svn: 319002
The goal of this commit is to fix clang-format so it does not merge tokens when
using the alternative spelling keywords. (eg: "not foo" should not become "notfoo")
The problem is that Preprocessor::HandleIdentifier used to drop the identifier info
from the token for these keyword. This means the first condition of
TokenAnnotator::spaceRequiredBefore is not met. We could add explicit check for
the spelling in that condition, but I think it is better to keep the IdentifierInfo
and handle the operator keyword explicitly when needed. That actually leads to simpler
code, and probably slightly more efficient as well.
Another side effect of this change is that __identifier(and) will now work as
one would expect, removing a FIXME from the MicrosoftExtensions.cpp test
Differential Revision: https://reviews.llvm.org/D35172
llvm-svn: 308008
There's a Microsoft header in the Windows SDK which won't
compile with clang because it uses an operator name (and)
as a field name. This patch allows that file to compile by
setting the option which disables operator names.
The header which doesn't compile <Query.h> C:/Program Files (x86)/
Windows Kits/10/include/10.0.14393.0/um\Query.h:259:40:
error: expected member name or ';' after declaration specifiers
/* [case()] */ NODERESTRICTION or;
~~~~~~~~~~~~~~~ ^
1 error generated.
Contributed for Melanie Blower
Differential Revision:https://reviews.llvm.org/D33505
llvm-svn: 303798
Although not specifically mentioned in the documentation, MSVC accepts
__uuidof(…) and declspec(uuid("…")) attributes on enumeration types in
addition to structs/classes. This is meaningful, as such types *do* have
associated UUIDs in ActiveX typelibs, and such attributes are included
by default in the wrappers generated by their #import construct, so they
are not particularly unusual.
clang currently rejects the declspec with a –Wignored-attributes
warning, and errors on __uuidof() with “cannot call operator __uuidof on
a type with no GUID” (because it rejected the uuid attribute, and
therefore finds no value). This is causing problems for us while trying
to use clang-tidy on a codebase that makes heavy use of ActiveX.
I believe I have found the relevant places to add this functionality,
this patch adds this case to clang’s implementation of these MS
extensions. patch is against r285994 (or actually the git mirror
80464680ce).
Both include an update to test/Parser/MicrosoftExtensions.cpp to
exercise the new functionality.
This is my first time contributing to LLVM, so if I’ve missed anything
else needed to prepare this for review just let me know!
__uuidof: https://msdn.microsoft.com/en-us/library/zaah6a61.aspx
declspec(uuid("…")): https://msdn.microsoft.com/en-us/library/3b6wkewa.aspx
#import: https://msdn.microsoft.com/en-us/library/8etzzkb6.aspx
Reviewers: aaron.ballman, majnemer, rnk
Differential Revision: https://reviews.llvm.org/D26846
llvm-svn: 289567
Some Windows SDK classes, for example
Windows::Storage::Streams::IBufferByteAccess, use the ATL way of spelling
attributes:
[uuid("....")] class IBufferByteAccess {};
To be able to use __uuidof() to grab the uuid off these types, clang needs to
support uuid as a Microsoft attribute. There was already code to skip Microsoft
attributes, extend that to look for uuid and parse it. Use the new "Microsoft"
attribute type added in r280575 (and r280574, r280576) for this.
Final part of https://reviews.llvm.org/D23895
llvm-svn: 280578
Clang used to silently ignore __declspec(novtable). It is implemented
now, but leaving the vtable uninitialized does not work when using the
Itanium ABI, where the class layout for complex class hierarchies is
stored in the vtable. It might be possible to honor the novtable
attribute in some simple cases and either report an error or ignore
it in more complex situations, but it’s not clear if that would be
worthwhile. There is also value in having a simple and predictable
behavior, so this changes clang to simply ignore novtable when not using
the Microsoft C++ ABI.
llvm-svn: 242730
This reverts commit r239846 and r239879. They caused clang's
-fms-extensions behavior to incorrectly parse lambdas and includes a
testcase to ensure we don't regress again.
This issue was found in PR24027.
llvm-svn: 241668
__declspec(align(...)) is unlike all other attributes in that it is not
applied to a variable if it appears before the class-key. If the
tag in question isn't part of a variable declaration, it is not ignored.
Instead, the alignment attribute is applied to the tag.
This fixes PR18024.
llvm-svn: 235272
We'd diagnose an __assume expression which contained a function call.
This would result in us wrongly returning ExprError, causing mysterious
failures later on.
llvm-svn: 230597
It is common for COM interface classes to be marked as 'novtable' to
tell the compiler that constructors and destructors should not reference
virtual function tables.
This commit implements this feature in clang.
llvm-svn: 227796
So, place warning about property getter should not be used for side-effect
under its own group so warning can be turned off.
rdar://19137815
llvm-svn: 224479
We would crash trying to treat a property member as a field. These
shoudl be forbidden anyway, reject programs which contain them.
This fixes PR21840.
llvm-svn: 224193
This CL has caused bootstrap failures on Linux and OSX buildbots running with -Werror.
Example report from http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/13183/steps/bootstrap%20clang/logs/stdio:
================================================================
[ 91%] Building CXX object tools/clang/tools/diagtool/CMakeFiles/diagtool.dir/ShowEnabledWarnings.cpp.o
In file included from /home/dtoolsbot/build/sanitizer-x86_64-linux/build/llvm/lib/Target/R600/AMDGPUISelDAGToDAG.cpp:20:
In file included from /home/dtoolsbot/build/sanitizer-x86_64-linux/build/llvm/lib/Target/R600/SIISelLowering.h:19:
/home/dtoolsbot/build/sanitizer-x86_64-linux/build/llvm/lib/Target/R600/SIInstrInfo.h:71:8: error: 'getLdStBaseRegImmOfs' overrides a member function but is not marked 'override' [-Werror,-Winconsistent-missing-override]
bool getLdStBaseRegImmOfs(MachineInstr *LdSt,
^
/home/dtoolsbot/build/sanitizer-x86_64-linux/build/llvm/include/llvm/Target/TargetInstrInfo.h:815:16: note: overridden virtual function is here
virtual bool getLdStBaseRegImmOfs(MachineInstr *LdSt,
^
================================================================
llvm-svn: 218969
for an overriding method if class has at least one
'override' specified on one of its methods.
Reviewed by Doug Gregor. rdar://18295240
(I have already checked in all llvm files with missing 'override'
methods and Bob Wilson has fixed a TableGen of FastISel so
no warnings are expected from build of llvm after this patch.
I have already verified this).
llvm-svn: 218925
Fixes build for SPEC 2000 CPU. MSVC disables these aliases under /Za,
which enables stricter standards compliance. We don't currently have any
way to disable them.
Patch by Kevin Smith!
llvm-svn: 216270
This is a follow-up to David's r211677. For the following code,
we would end up referring to 'foo' in the initializer for 'arr',
and then fail to link, because 'foo' is dllimport and needs to be
accessed through the __imp_?foo.
__declspec(dllimport) extern const char foo[];
const char* f() {
static const char* const arr[] = { foo };
return arr[0];
}
Differential Revision: http://reviews.llvm.org/D4299
llvm-svn: 211736
With recent changes, this is now a compatible language extension and can be
safely enabled with -ms-extensions instead of requiring the full
-ms-compatibility MSVC drop-in mode. As such we can now also emit an extension
warning under -Wmicrosoft to help users port their code.
llvm-svn: 209978
MSVC and clang with -fms-extensions allow pure virtual methods to be
defined inline after the "= 0" tokens. Clang warns on these because it
is not standard, but incorrectly warns on out-of-line definitions, which
are standard.
With this change, clang will only warn on inline definitions of pure
virtual methods.
Fixes some self-host warnings on out-of-line definitions of pure virtual
destructors.
llvm-svn: 192244
We previously handled one-dimensional arrays but didn't consider the
general case. The fix is simple: keep going through subsequent
dimensions until we get to the base element.
llvm-svn: 191493
Summary:
__uuidof on templated types should exmaine if any of its template
parameters have a uuid declspec. If exactly one does, then take it.
Otherwise, issue an appropriate error.
Reviewers: rsmith, thakis, rnk
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1419
llvm-svn: 190240
Summary:
Transform the token sequence for:
typename typedef T U;
to:
typename T typedef U;
Raise a diagnostic when this happens but only if we succeeded handling
the typename.
Reviewers: rsmith, rnk
Reviewed By: rsmith
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1433
llvm-svn: 189867
Summary:
There were two things known to be wrong with our implementation of MSVC
mode template arguments:
- We didn't properly handle __uuidof/CXXUuidofExpr and skipped all type
checking completely.
- We didn't allow for MSVC's extension of allowing certain constant
"foldable" expressions from showing up in template arguments.
They allow various casts dereference and address-of operations.
We can make it more general as we find further peculiarities but this
is the known extent.
Reviewers: rsmith, doug.gregor, rjmccall
Reviewed By: doug.gregor
CC: cfe-commits, rnk
Differential Revision: http://llvm-reviews.chandlerc.com/D1444
llvm-svn: 189087
